The demand for further
miniaturization of electronic devices, which is expected to lead the
today´s CMOS based technology to its practicable and physical
limit within the next ten to twenty years (ITRS),
triggers an intense research in the field of "Molecular Electronics". Using molecules as building
electronic devices will be promising due to several reasons. Conduction
processes in molecular units involve only few to single electrons. This
lower the energy consumption to a minimum. Molecules or molecular
blocks can be chemically tailored with respect to their size, structure
electronic properties (e.g. wire, diode, switch). Furthermore,
self-organization processes for the bottom-up fabrication of devices
significantly lower the fabrication costs. Nevertheless,
implementing molecular units into electronic devices working with the
robustness and reliability such as the CMOS-based devices will be a
challenge. Several obstacles have to be overcome, as the detailed
of charge transport processes as well as controllable and reliable
of the molecules to the macroscopic “outer” world. All this requires a
interdisciplinary research, involving chemists, physicists, materials
scientists and engineers.
embodies the scientific background of the Virtual Insitute of
Systems for Information Technology (IFMIT). IFMIT was founded in 2004 within
the framework of the Initiative and
Networking Fund of the Helmholtz
Association. The following groups of the RWTH Aachen University
and the Research Center Jülich collaborate within this
framework on research topics that are related to basic questions of
charge transport properties of functional molecules:
group of Prof.
Ulrich Simon, Institute of Inorganic Chemistry, RWTH Aachen
University, is concerned with the synthesis of functional molecules and
ligand stabilized metal nanoparticles.
group of Prof. Maarten
Herbert Schoeller), Institute of Theoretical
Physics A, RWTH Aachen University, is concerned with theoretical
group of Dr. Silvia
Karthäuser (Prof. Dr. Reiner Waser) investigates charge
transport characteristics of functional molecules by scanning probe
techniques in UHV (UHV-STM/STS).
scan of BP4 inserted into an higly ordered SAM of dodecanethiol (C12).
Bright spots represent single BP4 molecules.
group of Prof.
Thomas Wandlowski investigates structural and charge transport
characteristics of functional molecules by electrochemical based
scanning tunneling techniques ("electrochemical based break-junction"
Principle of the electrochemical single molecule
(A) disabling of the STM feedback at a relative distance zo (defined by
io = 100 pA and (EWE1 – EWE2) = 0.10 V) and approach; (B) formation of
molecular junctions; (C) stretching with a constant pulling rate of 6
nm s-1; (D) breaking of the contact and switching on the feedback
The statistical analysis of up to 3000 individual pulling curves yields
the values of the single junction conductance.